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        riddles >> easy >> 7+7=12?
        
(Message started by: Aurora on May 25th, 2007, 8:26am)
Title: 7+7=12?
Post by Aurora on May 25th, 2007, 8:26am
Prove that seven is half of twelve.
Title: Re: 7+7=12?
Post by fatball on May 25th, 2007, 8:33am
folding the paper  ;D
Title: Re: 7+7=12?
Post by Aurora on May 25th, 2007, 10:45pm
Sorry fatball, not quite sure where you're coming from, you'll have to explain. ???

Either that or my brain's not quite switched on this early on a Saturday morning.
Title: Re: 7+7=12?
Post by jollytall on May 25th, 2007, 10:51pm
Ask the Romans instead.
Title: Re: 7+7=12?
Post by towr on May 26th, 2007, 9:29am
An extra finger on each hand might explain it.
Title: Re: 7+7=12?
Post by fatball on May 26th, 2007, 6:42pm

on 05/25/07 at 22:45:41, Aurora wrote:
Sorry fatball, not quite sure where you're coming from, you'll have to explain. ???
Combine my answer with jollytall's Roman letter answer.
Title: Re: 7+7=12?
Post by Aurora on May 27th, 2007, 12:28am
Thought that was probably what you meant, just wanted to check.

As I said, my brain's not always up and running that early!
Title: Re: 7+7=12?
Post by Grimbal on May 27th, 2007, 5:30am
Else we could use the well-known fact that 1=0, that has been proven numerous times.  ;)
Title: Re: 7+7=12?
Post by Sir Col on May 27th, 2007, 5:44am
The following method fails slightly in addressing half of "twelve" being seven, but it does explain 7 + 7 = 12...

7 + 1 = 8
7 + 2 = 9
7 + 3 = A
7 + 4 = B
7 + 5 = 10
7 + 6 = 11
7 + 7 = 12

;)
Title: Re: 7+7=12?
Post by ThudanBlunder on May 27th, 2007, 5:56am
and there is no solution to

  SEVEN
+ SEVEN
--------
TWELVE
--------
Title: Re: 7+7=12?
Post by jollytall on May 27th, 2007, 11:59am
Btw. I think the captioned question is a typical example when a good riddle is rephrased into something that is almost the same, but still incorrect.
While in this case the original riddle was, as said in the first post as well: "Prove that seven is half of twelve." and it can be solved as hinted above, actually the hinted method does not give a solution to the captioned question of "7+7=12?" unless you use [hide]transparent paper[/hide]. But because the riddle is so well known we simple omited this liitle fact.
If you want to phrase the question "A+B=C?" then you can try "6+4=9?" or "6+4=11?" instead.
Title: Re: 7+7=12?
Post by fatball on May 27th, 2007, 9:42pm
You don't need transparent paper, as long as you can see one side of the folded paper, that gives you the answer already.
Title: Re: 7+7=12?
Post by jollytall on May 27th, 2007, 10:11pm
How?
It is true then that 7 is the half of 12 (first post question).
But I do not see, how you can make 7+7 equal to 12 (question in the subject).
Title: Re: 7+7=12?
Post by Aurora on May 27th, 2007, 10:49pm
I didn't mean to cause any confusion. I only called the thread "7+7=12?" too avoid giving away the ridddle in the title. That was the title given when I first came across it. Although if anyone could prove this as well, I would like to know the answer.
Title: Re: 7+7=12?
Post by wangsacl on May 28th, 2007, 2:40am
I think this is the answer.
I don't know how to hide it, so you'll see many bars. After that is answers.

















































As you know 12 is XII, wroten in Roman Numerals. Divide XII with straight lines, to become XII. You see the top part, is VII. So, 12 divided to 2 is 7, or, 2 times 7 is 12, or, 7+7=12
I hope this is the right one.
Title: Re: 7+7=12?
Post by Aurora on May 28th, 2007, 7:01am
Welcome to the forum wangsacl.

That was the answer that I was looking for, (hinted at heavily by fatball and jollytall!). To hide something, highlight it and select the hide icon (far right, bottom row). At this stage in a thread, after big hints, hiding the answer isn't that important, it's just so that people browsing won't accidently stumble upon solutions.

In the meantime, enjoy solving the riddles!
Title: Re: 7+7=12?
Post by Grimbal on May 28th, 2007, 8:53am

on 05/27/07 at 05:56:59, ThudanBlunder wrote:
and there is no solution to

  SEVEN
+ SEVEN
--------
TWELVE
--------

Not in an even base, at least.
Title: Re: 7+7=12?
Post by ThudanBlunder on May 28th, 2007, 10:10am

on 05/28/07 at 08:53:10, Grimbal wrote:
Not in an even base, at least.

If you are looking for something to chew on, Grimbal, try this addition (base 10):


   TWO
 THREE  
 SEVEN
--------
TWELVE
--------

:)
Title: Re: 7+7=12?
Post by fatball on May 28th, 2007, 10:28am
To start without much thought...

[hide]T must be 1 => W must be 0.

S can be 8 or 9 depending on the prevous column.

H+E=E is interesting.  Since H cannot be 0, it has to be 9 for the equation to work, hence S must be 8.

The letters outstanding are E, R, V, L, N, O and the numbers outstanding are 2, 3, 4, 5, 6, 7.

[/hide]To be continued...
Title: Re: 7+7=12?
Post by Grimbal on May 28th, 2007, 11:30am
Note that O and N are exchangeable.
Title: Re: 7+7=12?
Post by Icarus on Jun 3rd, 2007, 3:18pm
Just out of curiosity, who caught the significance of towr's thoughtful reply?


on 05/26/07 at 09:29:47, towr wrote:
An extra finger on each hand might explain it.
Title: Re: 7+7=12?
Post by JiNbOtAk on Jun 3rd, 2007, 5:53pm

on 06/03/07 at 15:18:13, Icarus wrote:
Just out of curiosity, who caught the significance of towr's thoughtful reply?


Not sure myself, maybe A & B ?
Title: Re: 7+7=12?
Post by Sir Col on Jun 3rd, 2007, 11:57pm

on 06/03/07 at 15:18:13, Icarus wrote:
Just out of curiosity, who caught the significance of towr's thoughtful reply?

Just out of curiosity, who caught the significance of Sir Col's thoughtful reply to towr's?

(Actually I should have quoted him to make the connection more explicit.)
Title: Re: 7+7=12?
Post by TruthlessHero on Jun 4th, 2007, 1:06am
Can you provide a little more insight into A and B please? It's probably the hour, but I can't really put them together with everything.
Title: Re: 7+7=12?
Post by BNC on Jun 4th, 2007, 1:53am

on 06/04/07 at 01:06:49, TruthlessHero wrote:
Can you provide a little more insight into A and B please? It's probably the hour, but I can't really put them together with everything.


we (humans) have 10 finger, hence the decimal system with 10 digits (0..9).
Assume we had 6 fingers on each hand (12 overall). It is likelly we would have a 12-based (duadecimal?) counting system, with twelve digits. Call these digits 0..9,A,B.

If you add 7 and 7 using this system, you get 12, because 1212=1410.

You can simply try it: let's add 7 to 7:
7.. 8,9,A,B,10,11,12
Title: Re: 7+7=12?
Post by TruthlessHero on Jun 4th, 2007, 6:03am
I see, thanks for the clarification.
Title: Re: 7+7=12?
Post by srn347 on Aug 28th, 2007, 4:44pm
Base 12 or more likely the roman numeral.


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